Solve for $x$ and $y$ using substitution. ${-4x+2y = 6}$ ${y = 4x+7}$
Answer: Since $y$ has already been solved for, substitute $4x+7$ for $y$ in the first equation. ${-4x + 2}{(4x+7)}{= 6}$ Simplify and solve for $x$ $-4x+8x + 14 = 6$ $4x+14 = 6$ $4x+14{-14} = 6{-14}$ $4x = -8$ $\dfrac{4x}{{4}} = \dfrac{-8}{{4}}$ ${x = -2}$ Now that you know ${x = -2}$ , plug it back into $\thinspace {y = 4x+7}\thinspace$ to find $y$ ${y = 4}{(-2)}{ + 7}$ $y = -8 + 7$ $y = -1$ You can also plug ${x = -2}$ into $\thinspace {-4x+2y = 6}\thinspace$ and get the same answer for $y$ : ${-4}{(-2)}{ + 2y = 6}$ ${y = -1}$